added logger

src/de/miaurizius/jgame2d/core/Boot.java

@@ -1,10 +1,13 @@
 package de.miaurizius.jgame2d.core;
 
 import javax.swing.*;
+import java.util.logging.Logger;
 
 public class Boot {
 
-    public static void main() {
+    public static final Logger logger = Logger.getLogger("JDGame2D");
+
+    static void main() {
         JFrame window = new JFrame();
         window.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
         window.setResizable(false);

src/de/miaurizius/jgame2d/core/Sound.java

@@ -6,6 +6,8 @@ import javax.sound.sampled.Clip;
 import java.io.File;
 import java.net.MalformedURLException;
 import java.net.URL;
+import java.util.logging.Level;
+import java.util.logging.Logger;
 
 public class Sound {
 
@@ -20,7 +22,7 @@ public class Sound {
             soundURL[3] = new File("assets/sounds/unlock.wav").toURI().toURL();
             soundURL[4] = new File("assets/sounds/fanfare.wav").toURI().toURL();
         } catch(MalformedURLException e) {
-            e.printStackTrace();
+            Boot.logger.log(Level.SEVERE, e.getMessage());
         }
     }